Tappets not going quiet?

P

Pee Sicks

New Member
Hi,
Having a fairly unusual issue with my P6 at present. I have just fitted a new camshaft and lifters, the cam was run in correctly at 2000rpm for 20 mins, but the tappets refuse to go quiet.
I have carried out an oil change, this did nothing.
When driving, the tappets get ridiculously loud as engine speed increases, to the point that the engine is misfiring and losing power. When the car slows down, the tappets begin to quieten, but never fully. At idle they are faintly chattering.
I have checked pre-load, but all engine components are standard so don't see this being an issue.
The oil pressure gauge is showing around 30psi when hot, I can clearly see oil dripping from the rocker shafts so presumably it's moving round the engine ok.
Anyone seen this before? Is it likely to sort itself?
All replies gratefully received.

Regards,
Stu.
 
Hi Stu .
What's the situation with your rocker gear and shafts ? Were they replaced , checked over ? Push rods too , checked for straight , length , wear ? If no i'd lift the rocker covers and take a look for lost motion in the rocker gear somewhere . see if you can rotate a pushrod or move a rocker . That's where i'd start , assuming your confident the cam and lifters are installed correctly .
:D
 
stina said:
see if you can rotate a pushrod or move a rocker
Click to expand...

Might be on to something there......you can turn a few of the pushrods by hand. I've a spare set of rocker shafts, might give them a try. :D

Thanks,
Stu.
 
Inspect closely the under side of the rockers in the cups that take the push rods , look for the hardened insert having broken up and disappeared ! :D
 
Fitted my spare set of rockers/shafts this morning, these have no obvious wear on shafts or rocker arms. I also changed the oil again, refilling with Penrite Classic Light 20W/60.
At low road/engine speed the engine is quiet enough, but even a short motorway run leaves the top end very noisy and a drop in power, coming off the slip road I suspect the car was running on 5 or 6 cylinders.
The oil pressure sits right on 30psi when the engine is hot, but the pressure never goes above this, regardless of engine speed. I've checked the operation of the relief valve, the plunger is sliding smoothly in the bore so I assume this is correct.
I re-primed the pump after reassembling the relief valve, and upon starting it sounded like the bottom end has gone :(
Sump off next I think, or might be a cheap P6 needing a new crank up for sale soon!
 
Pee Sicks said:
I re-primed the pump after reassembling the relief valve, and upon starting it sounded like the bottom end has gone :(
Sump off next I think, or might be a cheap P6 needing a new crank up for sale soon!
Click to expand...

How did you do this , and did it prime up and put the oil light out ? Did you prime it with a drill ? worth doing again , you should feel a load on the drill as it primes up . If you've had the rocker gear off they can take a while to pump back up and run smooth .
 
Stina, I'd primed the oil pump with my drill, I did feel resistance build up as the pump primed, but not as much resistance as I'd expected. The drill didn't slow down much, though I could definitely hear oil and air escaping inside the engine.
I pulled the sump off this morning, the bottom end is OK, no wear on the bearing shells.
One thing I did notice was the huge ant-hill of crap in the sump, directly under the oil strainer. I wonder if this was getting sucked against the strainer and restricting the flow? It was lots of little bits, little black flakes and old bits of gasket, sealant etc. Cleaned the sump out with diesel, all sparkly now!
At least the big-ends are OK, which was a real concern.
Ordered a bottom end gasket set, so will let you know when I get the bottom end back together.
Regards
Stu.
 
Pee Sicks said:
One thing I did notice was the huge ant-hill of crap in the sump, directly under the oil strainer. I wonder if this was getting sucked against the strainer and restricting the flow?
Click to expand...

That can happen. I've not experienced it on the RV8, but the Ford CVH used be prone to it for some reason, and they would get the noisy tappets as well. The only other symptom was a whine as the pump struggled to pull the oil through the blocked strainer.
 
OK, bottom end all back together again, new oil and filter, oil pump packed with Vaseline, primed up with the drill.
Oil pressure much better now, 30 psi idling hot, 40-45ish when driving.
One tappet is refusing to be quiet now! The noise comes and goes so suspicious that the tappet is faulty. I'm going to run the car for a few weeks and see if it gets better, I can't really be bothered pulling the inlet manifold off again.
Next time I will buy Genuine/OE lifters, not the cheap ones.
Thanks to all to who offered advice, it is much appreciated :D

Regards,
Stu.
 
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